Structure and function of traditional agroforestry systems in the western Himalaya. II. Nutrient cycling

TitleStructure and function of traditional agroforestry systems in the western Himalaya. II. Nutrient cycling
Publication TypeJournal Article
Year of Publication1989
AuthorsToky, OP, Kumar, P, Khosla, PK
JournalAgroforestry Systems
Volume9
Issue1
Pagination71-89
Date PublishedAugust 1989
LanguageEnglish
Keywordsagroforestry systems; allocation pattern; nutrient budget; nutrient cycling; soil fertility; Western Himalaya
Abstract

Budget of nutrient in plant and soil, and their rates of recycling in three types of traditional agroforestry systems in mid elevations of the western Himalaya were studied. Concentration of nitrogen and potassium was significantly higher in fruits and leaves than in branches, boles, and litter. Grewia optiva, an important fodder tree, was found to be rich in potassium, vegetable crops in nitrogen, and weeds in phosphorus. Maximum store of nutrients was estimated in aboveground biomass of agrihortisilvicultural system: nitrogen 532, phosphorus 40, potassium 461, calcium 400, and magnesium 298 kg/ha; it was closely followed by that in agrihorticultural system, and both these had about 2-fold higher nutrient stock as compared to agrisilvicultural system. In the case of the former two systems, considerable quantity of nutrients up to nitrogen 169, phosphorus 14, potassium 165, calcium 97, and magnesium 65 kg/ha, for example in agrihortisilvicultural system, was recycled through debris of crops and weeds, and tree leaf litter, while the recycling rate was almost half in agrisilvicultural system. Through 'harvest' potassium was depleted in the largest quantity from the system, followed by nitrogen, magnesium, calcium, and phosphorus; much higher loss occurred through agricultural and/or horticultural edible parts as compared to fuel and fodder biomass. For example, the loss through agricultural crops and horticultural fruits for nitrogen in agrihortisilvicultural system was up to 75 percent and 38 percent respectively of the total annual uptake. This heavy loss makes the system unstable from a nutrient point of view particularly for nitrogen and potassium until external inputs are added through organic and inorganic fertilizers. Agrihortisilvicultural system is remarkably efficient in view of biomass productivity for fuel, fodder and fruits, and also from nutrient point of view provided losses through harvest are compensated externally.

URLhttps://doi.org/10.1007/BF00120156
DOI10.1007/BF00120156
Journal Abbreviation

Agroforest Syst

ISSN

0167-4366; 1572-9680

Collection Topic: